It would be from the cartoon Animaniacs from the 90s. It would say, "Helloooooo, Nurse!" It would, possibly, have an accompanying picture of the Sexy Nurse, or perhaps of Yakko and Wakko.
Because I need this icon to become my internet equivalent of a wolf whistle so I can show shallow appreciation for sexily pretty pictures of people.
You can do it! :-)
ETA: Found! Props to boudecia7 for mad internet-fu skillz and fandomfrom3 for making icons from a 15 year-old show!